How to clean a block

[Tuna Joe]

Originally Posted by Woj

I've noticed on several TH400 Vin stampings that the last 3 or 4 digits are not even with the first digits. My guess is that the factory stamped the first two or three digits knowing the car would be in a certain range of a thousand cars and left the last three or four digits until later in the assembly.

Maybe that's the case here? The digits fonts are all good.

I don’t know what Ralph is talking about to be honest.
It looks good to me, broach marks are present, characters match other 68’ L89 blocks that are built close to the vin. And it’s been validated by the same guy that does all of Corvette Mike’s C3s.
I don’t really see the need to defend it.

[Tuna Joe]

My block was rusty in the water jackets so I cleaned the outside of the block really well to get the old grease off and then bought 8 gallons of Evaporust to try and remove the rust from inside.

I think I saw this technique done on this site so I found some heavy mil plastic and dropped the block inside the trash can lined with the plastic and then dumped the Evaporust in.

Filled the outside with water to compress the Evaporust and left it for a week.
Turned out pretty good!

[RPOLS3]

Does anyone "hot tank" blocks anymore? That used to be the best way to get them clean inside and out.

[Tuna Joe]

In California, who knows? This state makes it hard to do anything.